This invention relates to medical devices and more particularly to an implantable drug pump.
The medical device industry produces a wide variety of electronic and mechanical devices for treating patient medical conditions such as pacemakers, defribulators, neurostimulators, and therapeutic substance infusion devices. Medical devices can be configured to be surgically implanted or connected externally to the patient receiving treatment. Clinicians use medical devices alone or in combination with therapeutic substance therapies and surgery to treat patient medical conditions. For some medical conditions, medical devices provide the best, and sometimes the only, therapy to restore an individual to a more healthful condition and a fuller life. Implantable therapeutic substance infusion devices can be used to treat conditions such as pain, spasticity, cancer, and a wide variety of other medical conditions.
An implantable therapeutic substance infusion device is implanted by a clinician into a patient at a location appropriate for the therapy that interferes as little as practicable with patient activity. Typically, an infusion catheter is connected to the drug pump outlet and implanted to infuse the drug, infusate or other therapeutic substance at a programmed infusion rate and predetermined location to treat the medical condition. Reliable and accurate operation of the drug pump is important because both inadequate and unintended therapeutic substance infusion can create patient complications. In electrically powered implantable infusion devices, the period the infusion device can be implanted is often limited by factors such as battery consumption, corrosive damage, and mechanical wear. The relative large size of some implantable drug pumps can limit locations where the device can be implanted in a patient. An example of an implantable infusion device is shown in Medtronic, Inc. xe2x80x9cSynchroMed(copyright) Infusion Systemxe2x80x9d Product Brochure (1995).
Many drug pumps are configured, so the pump can be replenished with drug through the septum of a refill port while the pump is implanted, so the period the pump can be implanted may not be limited by drug capacity. This is commonly done by injecting a hypodermic needle through the skin and into the septum thereby providing access to refill the reservoir. In such devices a catheter access port is often provided in addition to the refill port. The catheter access port is also accessible percutaneously by hypodermic needle. Its septum provides direct access to the catheter bypassing the pump and allows a bolus of drug or fluid medication to be administered directly into the body at the site of the catheter. The catheter access port can also be used as a diagnostic tool to troubleshoot the catheter or infusion problems. An example of an implantable drug pump having a catheter access port is shown in U.S. Pat. No. 6,293,922 xe2x80x9cApparatus And Method For Guiding And Limiting Access By Hypodermic Needles To Septum Of A Human Implantable Medical Treatment Devicexe2x80x9d by Haase (Sep. 25, 2001).
Although some clinicians view the catheter access port septum as desirable, some are uncomfortable with its presence. If a person refilling the reservoir incorrectly injects the drug into the catheter access port instead of the refill port, this results in the drug being administered directly to the body. This may potentially cause a fatal overdose of the drug or other serious problems.
Accordingly, a need exists for a device and method that denies injections of drug directly into the catheter access port.
An implantable pump catheter access port denial device is a denial device configured for placement into the catheter access port to prevent insertion of a needle into the catheter access port. The implantable pump comprises housing, a drug reservoir, a metering device, and a catheter access port. The drug reservoir is coupled to the housing and has a reservoir outlet. This reservoir outlet is coupled to a metering device that has its own metered outlet. The catheter access port is fluidly coupled to the metered outlet and is configured for receiving a needle to infuse drug directly into a catheter.